--- a/xpcom/ds/nsMathUtils.h
+++ b/xpcom/ds/nsMathUtils.h
@@ -104,7 +104,7 @@
 #ifdef WIN32
   // NOTE: '!!' casts an int to bool without spamming MSVC warning C4800.
   return !!_finite(aNum);
-#elif defined(XP_DARWIN)
+#elif 1
   // Darwin has deprecated |finite| and recommends |isfinite|. The former is
   // not present in the iOS SDK.
   return std::isfinite(aNum);
